Smoke detectors have been recognized as being very useful and desirable in providing an early warning of dangerous levels of smoke, usually due to fire. When such detectors go into alarm, they usually generate an audible alarm indicating output. Such detectors can be expected to draw in the order of 6-10 mA of current when in an alarm state. Some detectors will generate a visual output as well.
Underwriter's Laboratories imposes a minimum standard requirement of 85 dBA output level for battery operated smoke detectors. A need has been identified to provide increased levels of alarm indicating audible inputs to benefit people with hearing losses. Increasing the output level by 10 dB produces a subjective effect for in individual in the region corresponding to doubling the level of the audio output.
There is thus an identified need for battery powered smoke detectors which will produce increased levels of audio output beyond those usually available with known detectors. Preferably, increased levels of audio output could be achieved without significant additional expense in either the components required or the manufacturing processes used to fabricate the detectors.